The present invention relates to a dispenser and, more particularly, to a dispenser for pasty or flowable media which includes a container having a delivery opening, a piston displaceably guided on a wall of the container in forming a lower seal for the filled material, a guide part formed by the container wall on the other side of the piston, and a device with an externally located handle for displacing the piston in a direction of the delivery opening.
Dispensers of the forementioned type are particularly used for pasty medium such as toothpaste, cosmetics, and also for foods such as, for example, mayonnaise, mustard, etc.
Dispensers have been proposed wherein the piston travels upwards in the container through a type of pumping movement on an externally accessible pressure piece due to an overpressure or underpressure and advances the filled material or charge before it. The filled material is always discharged in a portionwise manner. Additionally, such dispensers require valves at the delivery opening in order to produce an underpressure or maintain an overpressure. Thus, dispensers such as proposed in, for example, DE-OS 29 01 717 and DE-OS 31 05 859 comprise a plurality of components which must be closely toleranced thereby resulting in a dispenser which is complicated and prone to failure.
Additionally, in, for example, DE-OS 29 41 416 and DE-OS 30 07 480, dispensers are proposed wherein the piston is additionally secured to prevent a retraction or sliding back following the stroke or lifting movement, in that it is, for example, constructed in the manner of a climbing piston, which is locked by expansion parts, locating devices or disposed on a guide rod/or on the container inner wall. These constructions are also complicated and lead to sealing problems. Furthermore, in, for example, DE-AS 16 07 905 and EP-OS 0 053 329, dispenses or propose wherein springs are provided for preventing the piston from dropping.
However, these pump-like functioning dispensers have a complicated construction and are also prone to failure. Additionally, they generally only permit a portionwise delivery so that they have to be operated several times when a larger quantity is to be dispensed.
Finally, dispensers of the aforementioned type have been proposed wherein the piston is mechanically moved by an external actuation, with the lifting movement being directly manually produced (German utility models 79 08 402 and 82 29 055) or by mechanical transmission means. The first-mentioned construction suffers from the disadvantage that the container becomes ever shorter on emptying. In a known construction of the latter type (DE-OS 30 26 659), a rack is connected to the bottom of the piston and is located in a guide part connected to the container. With the rack cooperates a pinion, which is mounted in the guide part and can be rotated from the outside. However, problems are caused in this case by the guidance of the rack, as well as by the mounting of the pinion. However, it is advantageous that the filled material can be dispensed in random portions. However, it is only possible to operate it with two hands, so that for many uses, e.g. for toothpaste, the dispenser cannot be used and can only be used to a limited extent for other purposes, e.g. for cosmetics and the like.
On the basis of dispensers of the latter construction, the aim underlying the present invention essentially resides in providing a simple and more operationally reliable dispenser formed from a minimum of components, which permits both a portionwise and a continuous dispensing of the material.
In accordance with advantageous features of the present invention, a dispenser for pasty or flowable media is provided which includes a guide part with a container of the dispenser having an axially parallel downwardly open slot corresponding to a total stroke of the piston and wherein a device for displacing the piston as formed from a double-walled slide guided on a guide part and engaging on the piston and which roughly corresponds to a length of the slot.
By virtue of the above noted features of the present invention, a dispenser is provided which comprises only two components, namely, the container and piston with the double-walled slide connected thereto.
Advantageously, the piston and slide are guided on the container wall by virtue of the provision of two side walls which engage on the container externally or internally on either side of the slot and the inner wall is connected at its upper end to a piston and at its lower end to the outer wall thereby insuring an adequate guidance of the piston.
The assembly of the two parts or components of the present invention is very simple in that after filling the container in the conventional manner, i.e. from the open bottom, the piston is inserted, the doubled-walled slide is mounted on the container wall edges adjacent to the slot. By sliding the external handle, the piston is moved in a direction of the delivery opening so as to advance the filled material disposed forwardly thereof and permit the material to pass out of the discharge opening. The quality of filled material discharged is exclusively determined by the sliding movement with the hand or finger so that individual portioning is possible.
Since there is no need to provide means in a vicinity of the delivery opening, the piston can be moved up to the opening so that the container may be completely empted. Additionally, the dispenser can be readily operated with one hand in that the dispenser is engaged in the vicinity of the lower guide part and the slide is advanced, for example, with the thumb of the user. The slide position provides a criterion for the fill level in the container and there is no need for separately securing the pistion against a return or sliding back movement although this generally does not occur. The piston can readily be advanced up to the filled material or moved for compressing the latter and the delivery opening can be positioned along a longitudinal axis of the container as well as laterally, for example, formed as a spout.
In accordance with further features of the present invention, a dispenser is provided, in at least a region containing the filled material with a guide overlapping an external wall of the doubled-walled slide. By virtue of this arrangement it is ensured that the doubled-walled slide, the two walls of which are only interconnected in a vicinity of the lower end, is stable in all positions as a result of the additional guide overlapping the outer wall. This particularly avoids a supporting of the outer slide wall, however, it is also possible in accordance with the present invention for the guide to extend to the lower end of the container guide part so that the outer slide wall is also externally guided over its entire length and over the entire stroke path. This additional guidance also contributes to the stabilization of the container wall and further insures a completely satisfactory guidance of the piston in the dispenser or container. Additionally, the overall guidance can be aided in that the inner and outer slide walls, which are, for example, partly cylindrical in accordance with the cross-sectional shape of the container, engage over a larger region of the container wall.
Advantageously, the handle of the dispenser is substantially or roughly level with the piston which leads to a favourable construction for handling purposes, in that the complete container can be engaged in a vicinity of the guide part while also providing an adequate clearance for pressing the slide.
In order to lead to an additional reinforcement or stiffening of the container into an improved guidance of the piston the piston has, on an underside thereof downwardly extending ribs engaging on the inner wall of the guide part of the container.
Additionally, in accordance with still further features of the present invention, the lower end of the slide may be shaped as a base guided in a guide part of the container and be connected by means of ribs 18 to the piston the additional base connected to the slide also formes the lower seal for the container guide part so that the construction is particularly satisfactory from an optical standpoint.
It is also possible in accordance with the present invention to provide a dispenser when the slide and/or the guide is provided with several notches or the like for enabling a portionwise delivery of the filled material, such an arrangement provides the option or the user to skip several notches so that the desired quantity is then discharged.
It is also possible in accordance with the present invention to provide a linear scale on the external portion of the container whereby a discharge of defined portions of a specific weight or volume can be realized.
In order to insure a complete emptying of the container, advantageously, according to the present invention, the contour of the piston is adapted to the top of the inner contour of the container in a vicinity of the delivery opening.
The inventive construction can be used with containers having a circular, oval, rectangular cross-section with rounded corners and the like in an equally advantage manner. Double-walled containers are also possible, it merely being necessary to provide corresponding guides in the jacket of both container walls. The discharge or delivery opening can also be constructed in the manner of a nozzle for squeezing out the filled material. It can also have inserts or cross-sections shaping the discharged strand. It is also possible to provide several channels in the vicinity of the delivery openings, so that different or different colored filled materials can be discharged in juxtaposed manner in one strand.
The invention is described in greater detail hereinafter relative to non-limitative embodiments and the attached drawings.